Altın, Süreyya | Özgüven, Melih

Article | 2011 | Fresenius Environmental Bulletin20 ( 3 ) , pp.631 - 638

This study analyzed the zinc transport in supported liquid membrane (SLM) systems in which different anionic (Aliquat336) and cationic (D2EHPA) carriers, different solvents (kerosene and toluene) and different feed (deionized water and HCl) / stripping solutions (H3PO4, HCl and H 2SO4) were used. The results were modeled according to steady state (Fick's first law) and non-steady state kinetics approaches and the concordance of the models was discussed. It was observed from the experimental studies that 80.4% zinc transport could be achieved when deionized water was used as feed solution, kerosene/ D2EHPA (0.01 M) as membrane soluti . . .on combination and H3PO4(0.5 M) as stripping solution. Whilst the zinc transport efficiency was found to be 86.5% when HCl (1.0 M) was used as feed solution, toluene-Aliquat336 (0.02 M) as membrane solution combination and HCl (0.5 M) as stripping solution. Modeling studies established that the nonsteady state approach better represented zinc transport. It was therefore concluded that the zinc transport mechanism was affected by interface reactions rather than diffusion. © by PSP Daha fazlası Daha az

Altın, Süreyya | Alemdar, Sonay | Altın, Ahmet | Yıldırım, Yılmaz

Article | 2011 | Separation Science and Technology46 ( 5 ) , pp.754 - 764

Selective removal of cadmium from wastewaters is very important, because cadmium is toxic for the environment and for human health. This work is a comprehensive study on the selective removal of Cd(II) from aqueous solutions by using a co-current flow flat sheet supported liquid membrane system. 4.4 × 10-4M Cd(II) concentration was used as a feed solution in the experiments. Toluene containing Aliquat 336 was used as the membrane liquid in the membrane system. Parameters such as the properties of feed and stripping solutions, carrier concentration, and flow rate, which have roles in transport of Cd(II) ions, were optimized. The effi . . .ciency of the system is expressed in terms of permeability and flux values, and transport efficiency. The optimum process conditions for the Cd(II) transport are experimentally found as follows: The feed solution as 2 M HCl, the carrier concentration as 0.1 M Aliquat 336, the stripping solution as 0.06 M EDTA, and the flow rates for the feed and stripping solutions as 50 mL/min and 80 mL/min, respectively. Under these conditions, the Cd(II) transport efficiency is found to be 82%. © Taylor & Francis Group, LLC Daha fazlası Daha az

Altın, Süreyya

Article | 2011 | INTERNATIONAL JOURNAL OF CHEMICAL REACTOR ENGINEERING9 , pp.754 - 764

This study aims to investigate color and COD removal efficiencies of electrocoagulation (EC) process for dye solutions simulated by using polyvinyl alcohol (PVA) and reactive dyestuff of Remazol Turquoise Blue (G-133). The two different electrode configurations, namely monopolar and bipolar, were examined to find out the better alternative intensifying the performance of the process. The results obtained from these tests show that an EC cell with bipolar electrodes has produced slightly higher color and COD removal efficiencies than that of an EC cell with monopolar electrodes. The best removal efficiencies have been found for the b . . .oth electrode configurations under the conditions that the time of electrolysis is 30 min, the constant direct current (DC) value 0.75 A and the initial pH value 3. Consequently, the bipolar electrode configuration (BPEC) has yielded 72.7 percent COD and 99.8 percent color removals while the monopolar electrode configuration (MPEC) producing 65.2 percent COD and 99.6 percent color removals Daha fazlası Daha az